Messages in this thread | | | Subject | Re: [PATCH v4 5/7] s390: vfio-ap: allow assignment of unavailable AP resources to mdev device | From | Tony Krowiak <> | Date | Wed, 19 Jun 2019 09:39:02 -0400 |
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On 6/18/19 2:49 AM, Harald Freudenberger wrote: > On 17.06.19 17:07, Tony Krowiak wrote: >> On 6/17/19 6:05 AM, Harald Freudenberger wrote: >>> On 13.06.19 21:39, Tony Krowiak wrote: >>>> The AP architecture does not preclude assignment of AP resources that are >>>> not available. Let's go ahead and implement this facet of the AP >>>> architecture for linux guests. >>>> >>>> The current implementation does not allow assignment of AP adapters or >>>> domains to an mdev device if the APQNs resulting from the assignment >>>> reference AP queue devices that are not bound to the vfio_ap device >>>> driver. This patch allows assignment of AP resources to the mdev device as >>>> long as the APQNs resulting from the assignment are not reserved by the AP >>>> BUS for use by the zcrypt device drivers and the APQNs are not assigned to >>>> another mdev device. >>>> >>>> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> >>>> --- >>>> drivers/s390/crypto/vfio_ap_ops.c | 231 ++++++++------------------------------ >>>> 1 file changed, 44 insertions(+), 187 deletions(-) >>>> >>>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c >>>> index 60efd3d7896d..9db86c0db52e 100644 >>>> --- a/drivers/s390/crypto/vfio_ap_ops.c >>>> +++ b/drivers/s390/crypto/vfio_ap_ops.c >>>> @@ -406,122 +406,6 @@ static struct attribute_group *vfio_ap_mdev_type_groups[] = { >>>> NULL, >>>> }; >>>> -struct vfio_ap_queue_reserved { >>>> - unsigned long *apid; >>>> - unsigned long *apqi; >>>> - bool reserved; >>>> -}; >>>> - >>>> -/** >>>> - * vfio_ap_has_queue >>>> - * >>>> - * @dev: an AP queue device >>>> - * @data: a struct vfio_ap_queue_reserved reference >>>> - * >>>> - * Flags whether the AP queue device (@dev) has a queue ID containing the APQN, >>>> - * apid or apqi specified in @data: >>>> - * >>>> - * - If @data contains both an apid and apqi value, then @data will be flagged >>>> - * as reserved if the APID and APQI fields for the AP queue device matches >>>> - * >>>> - * - If @data contains only an apid value, @data will be flagged as >>>> - * reserved if the APID field in the AP queue device matches >>>> - * >>>> - * - If @data contains only an apqi value, @data will be flagged as >>>> - * reserved if the APQI field in the AP queue device matches >>>> - * >>>> - * Returns 0 to indicate the input to function succeeded. Returns -EINVAL if >>>> - * @data does not contain either an apid or apqi. >>>> - */ >>>> -static int vfio_ap_has_queue(struct device *dev, void *data) >>>> -{ >>>> - struct vfio_ap_queue_reserved *qres = data; >>>> - struct ap_queue *ap_queue = to_ap_queue(dev); >>>> - ap_qid_t qid; >>>> - unsigned long id; >>>> - >>>> - if (qres->apid && qres->apqi) { >>>> - qid = AP_MKQID(*qres->apid, *qres->apqi); >>>> - if (qid == ap_queue->qid) >>>> - qres->reserved = true; >>>> - } else if (qres->apid && !qres->apqi) { >>>> - id = AP_QID_CARD(ap_queue->qid); >>>> - if (id == *qres->apid) >>>> - qres->reserved = true; >>>> - } else if (!qres->apid && qres->apqi) { >>>> - id = AP_QID_QUEUE(ap_queue->qid); >>>> - if (id == *qres->apqi) >>>> - qres->reserved = true; >>>> - } else { >>>> - return -EINVAL; >>>> - } >>>> - >>>> - return 0; >>>> -} >>>> - >>>> -/** >>>> - * vfio_ap_verify_queue_reserved >>>> - * >>>> - * @matrix_dev: a mediated matrix device >>>> - * @apid: an AP adapter ID >>>> - * @apqi: an AP queue index >>>> - * >>>> - * Verifies that the AP queue with @apid/@apqi is reserved by the VFIO AP device >>>> - * driver according to the following rules: >>>> - * >>>> - * - If both @apid and @apqi are not NULL, then there must be an AP queue >>>> - * device bound to the vfio_ap driver with the APQN identified by @apid and >>>> - * @apqi >>>> - * >>>> - * - If only @apid is not NULL, then there must be an AP queue device bound >>>> - * to the vfio_ap driver with an APQN containing @apid >>>> - * >>>> - * - If only @apqi is not NULL, then there must be an AP queue device bound >>>> - * to the vfio_ap driver with an APQN containing @apqi >>>> - * >>>> - * Returns 0 if the AP queue is reserved; otherwise, returns -EADDRNOTAVAIL. >>>> - */ >>>> -static int vfio_ap_verify_queue_reserved(unsigned long *apid, >>>> - unsigned long *apqi) >>>> -{ >>>> - int ret; >>>> - struct vfio_ap_queue_reserved qres; >>>> - >>>> - qres.apid = apid; >>>> - qres.apqi = apqi; >>>> - qres.reserved = false; >>>> - >>>> - ret = driver_for_each_device(&matrix_dev->vfio_ap_drv->driver, NULL, >>>> - &qres, vfio_ap_has_queue); >>>> - if (ret) >>>> - return ret; >>>> - >>>> - if (qres.reserved) >>>> - return 0; >>>> - >>>> - return -EADDRNOTAVAIL; >>>> -} >>>> - >>>> -static int >>>> -vfio_ap_mdev_verify_queues_reserved_for_apid(struct ap_matrix_mdev *matrix_mdev, >>>> - unsigned long apid) >>>> -{ >>>> - int ret; >>>> - unsigned long apqi; >>>> - unsigned long nbits = matrix_mdev->matrix.aqm_max + 1; >>>> - >>>> - if (find_first_bit_inv(matrix_mdev->matrix.aqm, nbits) >= nbits) >>>> - return vfio_ap_verify_queue_reserved(&apid, NULL); >>>> - >>>> - for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, nbits) { >>>> - ret = vfio_ap_verify_queue_reserved(&apid, &apqi); >>>> - if (ret) >>>> - return ret; >>>> - } >>>> - >>>> - return 0; >>>> -} >>>> - >>>> /** >>>> * vfio_ap_mdev_verify_no_sharing >>>> * >>>> @@ -529,18 +413,26 @@ vfio_ap_mdev_verify_queues_reserved_for_apid(struct ap_matrix_mdev *matrix_mdev, >>>> * and AP queue indexes comprising the AP matrix are not configured for another >>>> * mediated device. AP queue sharing is not allowed. >>>> * >>>> - * @matrix_mdev: the mediated matrix device >>>> + * @mdev_apm: the mask identifying the adapters assigned to mdev >>>> + * @mdev_apm: the mask identifying the adapters assigned to mdev >>> I assume you wanted to write @mdev_aqm ... queues ... at the 2nd line. >> >> You assumed correctly. I also mean to say "domains assigned to mdev". >> >>>> * >>>> * Returns 0 if the APQNs are not shared, otherwise; returns -EADDRINUSE. >>>> */ >>>> -static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev) >>>> +static int vfio_ap_mdev_verify_no_sharing(unsigned long *mdev_apm, >>>> + unsigned long *mdev_aqm) >>>> { >>>> struct ap_matrix_mdev *lstdev; >>>> DECLARE_BITMAP(apm, AP_DEVICES); >>>> DECLARE_BITMAP(aqm, AP_DOMAINS); >>>> list_for_each_entry(lstdev, &matrix_dev->mdev_list, node) { >>>> - if (matrix_mdev == lstdev) >>>> + /* >>>> + * If either of the input masks belongs to the mdev to which an >>>> + * AP resource is being assigned, then we don't need to verify >>>> + * that mdev's masks. >>>> + */ >>>> + if ((mdev_apm == lstdev->matrix.apm) || >>>> + (mdev_aqm == lstdev->matrix.aqm)) >>>> continue; >>>> memset(apm, 0, sizeof(apm)); >>>> @@ -550,12 +442,10 @@ static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev) >>>> * We work on full longs, as we can only exclude the leftover >>>> * bits in non-inverse order. The leftover is all zeros. >>>> */ >>>> - if (!bitmap_and(apm, matrix_mdev->matrix.apm, >>>> - lstdev->matrix.apm, AP_DEVICES)) >>>> + if (!bitmap_and(apm, mdev_apm, lstdev->matrix.apm, AP_DEVICES)) >>>> continue; >>>> - if (!bitmap_and(aqm, matrix_mdev->matrix.aqm, >>>> - lstdev->matrix.aqm, AP_DOMAINS)) >>>> + if (!bitmap_and(aqm, mdev_aqm, lstdev->matrix.aqm, AP_DOMAINS)) >>>> continue; >>>> return -EADDRINUSE; >>>> @@ -564,6 +454,17 @@ static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev) >>>> return 0; >>>> } >>>> +static int vfio_ap_mdev_validate_masks(unsigned long *apm, unsigned long *aqm) >>>> +{ >>>> + int ret; >>>> + >>>> + ret = ap_apqn_in_matrix_owned_by_def_drv(apm, aqm); >>>> + if (ret) >>>> + return (ret == 1) ? -EADDRNOTAVAIL : ret; >>>> + >>>> + return vfio_ap_mdev_verify_no_sharing(apm, aqm); >>>> +} >>>> + >>>> /** >>>> * assign_adapter_store >>>> * >>>> @@ -602,6 +503,7 @@ static ssize_t assign_adapter_store(struct device *dev, >>>> { >>>> int ret; >>>> unsigned long apid; >>>> + DECLARE_BITMAP(apm, AP_DEVICES); >>>> struct mdev_device *mdev = mdev_from_dev(dev); >>>> struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); >>>> @@ -616,32 +518,19 @@ static ssize_t assign_adapter_store(struct device *dev, >>>> if (apid > matrix_mdev->matrix.apm_max) >>>> return -ENODEV; >>>> - /* >>>> - * Set the bit in the AP mask (APM) corresponding to the AP adapter >>>> - * number (APID). The bits in the mask, from most significant to least >>>> - * significant bit, correspond to APIDs 0-255. >>>> - */ >>>> - mutex_lock(&matrix_dev->lock); >>>> - >>>> - ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid); >>>> - if (ret) >>>> - goto done; >>>> + memset(apm, 0, ARRAY_SIZE(apm) * sizeof(*apm)); >>> What about just memset(apm, 0, sizeof(apm)); >> >> apm is a pointer to an array of unsigned long, so sizeof(apm) will >> yield the number of bytes in the pointer (8), not the number of bytes in >> the array (32); or am I wrong about that? > The > DECLARE_BITMAP(apm, AP_DEVICES); > with the macro definition in types.h: > #define DECLARE_BITMAP(name,bits) \ > unsigned long name[BITS_TO_LONGS(bits)] > gives this expanded code: > unsigned long apm[BITS_TO_LONGS(AP_DEVICES)]; > which is an ordinary unsigned long array. > So sizeof(apm) gives the size of the array in bytes: > sizeof(apm) = 32 > I know this is weird, but it is common practice.
It must be the compiler figures out that apm points to an array. Although probably not necessary, I will make the change.
> > Funnily look at this code: > int blubber[10]; > int *ptr = blubber; > sizeof(blubber) gives 10*sizeof(int) but > sizeof(ptr) gives the size of the pointer pointing to > the blubber array. > >> >>>> + set_bit_inv(apid, apm); >>>> + mutex_lock(&matrix_dev->lock); >>>> + ret = vfio_ap_mdev_validate_masks(apm, matrix_mdev->matrix.aqm); >>>> + if (ret) { >>>> + mutex_unlock(&matrix_dev->lock); >>>> + return ret; >>>> + } >>>> set_bit_inv(apid, matrix_mdev->matrix.apm); >>>> - >>>> - ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev); >>>> - if (ret) >>>> - goto share_err; >>>> - >>>> - ret = count; >>>> - goto done; >>>> - >>>> -share_err: >>>> - clear_bit_inv(apid, matrix_mdev->matrix.apm); >>>> -done: >>>> mutex_unlock(&matrix_dev->lock); >>>> - return ret; >>>> + return count; >>>> } >>>> static DEVICE_ATTR_WO(assign_adapter); >>>> @@ -690,26 +579,6 @@ static ssize_t unassign_adapter_store(struct device *dev, >>>> } >>>> static DEVICE_ATTR_WO(unassign_adapter); >>>> -static int >>>> -vfio_ap_mdev_verify_queues_reserved_for_apqi(struct ap_matrix_mdev *matrix_mdev, >>>> - unsigned long apqi) >>>> -{ >>>> - int ret; >>>> - unsigned long apid; >>>> - unsigned long nbits = matrix_mdev->matrix.apm_max + 1; >>>> - >>>> - if (find_first_bit_inv(matrix_mdev->matrix.apm, nbits) >= nbits) >>>> - return vfio_ap_verify_queue_reserved(NULL, &apqi); >>>> - >>>> - for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, nbits) { >>>> - ret = vfio_ap_verify_queue_reserved(&apid, &apqi); >>>> - if (ret) >>>> - return ret; >>>> - } >>>> - >>>> - return 0; >>>> -} >>>> - >>>> /** >>>> * assign_domain_store >>>> * >>>> @@ -748,6 +617,7 @@ static ssize_t assign_domain_store(struct device *dev, >>>> { >>>> int ret; >>>> unsigned long apqi; >>>> + DECLARE_BITMAP(aqm, AP_DEVICES); >>> AP_DEVICES -> AP_DOMAINS >> >> Copy and paste error, it should be AP_DOMAINS. >> >>>> struct mdev_device *mdev = mdev_from_dev(dev); >>>> struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); >>>> unsigned long max_apqi = matrix_mdev->matrix.aqm_max; >>>> @@ -762,27 +632,19 @@ static ssize_t assign_domain_store(struct device *dev, >>>> if (apqi > max_apqi) >>>> return -ENODEV; >>>> - mutex_lock(&matrix_dev->lock); >>>> - >>>> - ret = vfio_ap_mdev_verify_queues_reserved_for_apqi(matrix_mdev, apqi); >>>> - if (ret) >>>> - goto done; >>>> + memset(aqm, 0, ARRAY_SIZE(aqm) * sizeof(*aqm)); >>> memset(aqm, 0, sizeof(aqm)); >> >> See response above. >> >>>> + set_bit_inv(apqi, aqm); >>>> + mutex_lock(&matrix_dev->lock); >>>> + ret = vfio_ap_mdev_validate_masks(matrix_mdev->matrix.apm, aqm); >>>> + if (ret) { >>>> + mutex_unlock(&matrix_dev->lock); >>>> + return ret; >>>> + } >>>> set_bit_inv(apqi, matrix_mdev->matrix.aqm); >>>> - >>>> - ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev); >>>> - if (ret) >>>> - goto share_err; >>>> - >>>> - ret = count; >>>> - goto done; >>>> - >>>> -share_err: >>>> - clear_bit_inv(apqi, matrix_mdev->matrix.aqm); >>>> -done: >>>> mutex_unlock(&matrix_dev->lock); >>>> - return ret; >>>> + return count; >>>> } >>>> static DEVICE_ATTR_WO(assign_domain); >>>> @@ -868,11 +730,6 @@ static ssize_t assign_control_domain_store(struct device *dev, >>>> if (id > matrix_mdev->matrix.adm_max) >>>> return -ENODEV; >>>> - /* Set the bit in the ADM (bitmask) corresponding to the AP control >>>> - * domain number (id). The bits in the mask, from most significant to >>>> - * least significant, correspond to IDs 0 up to the one less than the >>>> - * number of control domains that can be assigned. >>>> - */ >>>> mutex_lock(&matrix_dev->lock); >>>> set_bit_inv(id, matrix_mdev->matrix.adm); >>>> mutex_unlock(&matrix_dev->lock); >>> >> >
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